1. Field of the Invention
The present invention is directed to syringes in the field of medicine, especially to an assembled syringe for administering powder medicament. According to the present invention a solvent bottle containing diluent communicates with a solute bottle containing powder via a connecting tube. The diluent is injected into the solute bottle through the connecting tube using pressure. After the powder is dissolved and mixed uniformly with the diluent, the mixed solution is injected directly into a patient or added to a transfusion bottle or a transfusion tube. Both the solvent bottle and the solute bottle are packaged into a sleeve to avoid contamination or cross-infection. Buckles provided on the plunger sleeve are fitted into restricting slots. The fitting of the slots and buckles restricts the syringe position, self-locking and controlling the magnitude of force by which the solute bottle communicates with the solvent bottle. This also allows control of the depth of insertion of the needle into the body, and prevents misoperation or damage during transport, fetching and using. The present invention is a novel design with industrial applicability and can be adapted to generalized use in the industries.
2. Description of the Related Technology
Conventionally in medical applications, syringes, vials and diluents are separately provided. When a nurse is preparing to inject powder medicament, such as penicillin, into the body of a patient, he/she has to pierce the needle of a syringe into a vial containing diluent, draw out the diluent into the syringe, pierce the needle of the syringe into a different vial containing the powder medicament, inject the diluent from the first vial into the second vial to dissolve the powder, then draw the mixed solution into the syringe again before administering it to the patient or adding it to a transfusion bottle or transfusion tube for bolus intravenous injection. The operation involves several medical components and is complicated. Contamination of the syringe or mishandling of the medicament may result. Such syringes must be handled with great care and skill, which may put a nurse operating the syringe under great stress.
A Chinese patent application entitled “Vial Type Pressurized Syringe for Powder Medicament” filed by some of the present inventors discloses a syringe structure that punctures an inner bladder of a vial containing the powder medicament by a needle provided on the front end of a plunger to uniformly mix the powder medicament under pressure with a diluent contained in a solute bottle before injection. This syringe structure is advantageous by its simplified structure but the following defects have been found during its use:
1. The inner bladder and the solute bottle are not provided with protective jackets and the inner ends of the inner bladder and the solute bottle are not provided with seal stoppers. The needle is not provided with a sheath. Contamination or cross-infection tends to happen due to poor sealing.
2. When a nurse is operating the syringe, it is very difficult for him/her to control the force applied to the plunger and the depth of injection of the needle.
3. The distance between the inner bladder and the solute bottle is very short, thus causing problems such as sway or damage due to engagement with each other. There may also be unintended communication during transportation, handling or operation.